When forced to summarize the general theory of relativity in one sentence: Time and space and gravitation have no separate existence from matter.

I no longer believed in the known God of the Bible, but rather in the mysterious God expressed in nature.

My interest in science was always essentially limited to the study of principles.... That I have published so little is due to this same circumstance, as the great need to grasp principles has caused me to spend most of my time on fruitless pursuits.

Do not grow old, no matter how long you live.

The aim of science is, on the one hand, as complete a comprehension as possible of the connection between perceptible experiences in their totality, and, on the other hand, the achievement of this aim by employing a minimum of primary concepts and relations.

There comes a time when the mind takes a higher plane of knowledge but can never prove how it got there.

A man must learn to understand the motives of human beings, their illusions, and their sufferings.